A record number of starfish are dying along the West Coast, as a disease turns their arms into "goo."

The
animals, also known as sea stars, are falling victim to sea star
wasting disease. It causes white lesions to develops along their arms,
which slowly spread and cause their arms to disintegrate.

"What's
happening? We don't know yet. We think it's bacterial," Pete Raimondi,
chairman of the Department of Ecology and Evolutionary Biology at the
University of California, Santa Cruz's Long Marine Lab, tells
CBSNews.com. "We also know that it can move between species. They get a
wound and the bacteria will just kind of eat the species away."

Researchers
first started reporting the die-off in June. In late August, marine
biologist Jonathan Martin, out for a Saturday scuba dive, noticed dead
starfish that looked like they'd had their arms chopped off, he told National Geographic. He posted video footage to You Tube and photos to Facebook.

Dead sea stars have since turned up along the coast from Alaska down
to Southern California. Raimondi says that the disease is likely
affecting the sea star population as far south as Mexico, though
researchers have not had a chance to collect data from that area.

In
the past, researchers have linked sea star wasting disease outbreaks to
warm ocean temperatures. The biggest die-off occurred along the coast
of Southern California from 1983-1984, during an El Nino year. It caused
some species to go locally extinct -- although they did eventually come
back. A smaller die-off wiped out some of the population in 1997-1998,
another El Nino year.

"We're not having an El Nino year this year. That's what's really troublesome about this," Raimondi added.

Until
researchers can properly map the outbreak, Raimondi added, it will be
difficult to determine the cause, or an underlying link between the
regional outbreaks.

"I don't think there's been a spread, but
it's likely that the same causal factors are contributing to these
separate outbreaks," he said.

So far, the disease has killed 95 percent of certain species in some
tide pools. The overall population numbers in the millions, Raimondi
said, but it is troubling to see such a large percentage die off in
individual tide pool. Sea stars have "profound effects on the rest of
community because they eat a lot," Raimondi said, adding that in the
absence of sea stars, the population of mussels -- not the edible kind
-- will expand tremendously.

A similar die-off event is decimating the population of the Asterias species of starfish along the U.S. East Coast. The event started in 2011 and has effected sea stars from Maine to New Jersey.

The
next big thing, Raimondi said, is to figure out what is causing this,
so that researchers can start to determine how to control the outbreak.
His lab is mapping local reports on an interactive site, as well as updating a news feed
as the outbreak continues. They are asking local divers to post their
findings to the site, in the hopes that they can start to identify a
pattern and then, eventually, a cause.